Electric switch



Aug. 2s, 1923.

1,466,671 s. H. TODD ELECTRIC SWITCH Filed March 18, 1921 2 sheets-Sheet 1 CID ug. Z8, 1923.

S. H. TODD ELECTRIC SWITCH Filed March 18, 1921 2 Sheets-Sheet C Patentedug. 28,

s UiT sunnita. Tom), or pETRorT, MICHIGAN.

' meenam swITcH.

.application aiea March -1e, 1921. seriai No. 453,484.

To all lwhom t may coiicem.:v

Beit known that I, SAMUEL H. Tono, a citizen of the United States, residing at` Detroit, in the county of W'ayne and State of Michigan iwhose post-office address is 13131 Lincoln Ave), have invented a certain new and useful Improvement inElectric Switches, of which the following isa full, clear, and exact description, reference being'had to the accompanying drawings.

This invention relates to electric switches and has for its main objects the provision of a switch which can be operated by a comparatively small amount of movement of the actuating member and provide a comp-aratively large and quick movement of the contact member; the provision fva switch of very small external dimensions which however shall be capable of making and breaking a circuit of considerable magnitude the provision of a simple and compact switch whose parts shall be of rugged construction; 'the provision `of a switch operating upon a new principle; while further objects'and advantages of this invention will become apparent as the description proceeds.l I have devised and produced this switch primarily for use in connection with a thermostatsuch as often used for the control of heat and ycold producing apparatus, and to the end of providing a mechanism which shall operate with a minimum spread of temperature, but v my improvements are susceptible of use in many other relations in the arts.

In the drawings accompanying and form'- ing a part of this application I have shown a preferred embodiment of my inventive idea, and yin this specification I have described such embodiment with particularity but I do not thereby limit myself to the constructions and arrangements of this ein.-

' bodiment in any degree 'Whatever except as Fig. 2 is a sectional view corresponding to.

the broken line 2 2 of Fig. 1 and looking in the direction ofthe arrows; Fig. v3 is a perspective view of one of the movable contact iiieiiibers; Fig. 4 is aperspective View of one of the spring hammers; Fig. 5 is a persulating material having at one end the lateral ears 2-2 whereby it may be secured to a suitable base 3 such for example as the cap of a thermostat whose movable member is indicated at 4. Formed in one face of the member 1 is a longitudinal groove 5 which terminates short ofthe margin of the block at the upper end as shown in Fig. 1; and formed in the opposite side of the blockis the screw-threaded recess 6 adapted for the reception of the hollow cap 7 also preferably made vof insulating material and having an aperture 8 for the conductor (notshown). Traversing this block at each side of' the groove 5 are the `coi'iducting sleeves 9-9,

having contact screws 10-10 located inside said recess and having secured to their opposite ends the fixed contact members of the switch. Each of these members comprises a base part 12 and a terminal Vportion 13, the latter being curved upwardly as shown in Fig. 1 and formed in twolclosely adjacent lingers having outturned tips laf-14 as shown in Fig. 2, each' of saiddevicesbeing made of resilient spring. metal of an electrically-condiicting nature such as spring copper.

Iigidly secured in the base of the groove 5 is a U-sliap'ed, metallic. channel-member 16 havinga forward projection 17 at the middle of each of its lips and having a projection 18 at the end of eachof its" lips. Be'- twecii the projection 18 are secured the extension pieces 19-19 to the sides of which are secured the supporting plates 20-20, the members 19-19- being spaced from the hot` tom of the member 16 as shown at 21-21- The movable contact-member comprises two U-shaped pieces rigidly connected together base to base. one of said pieces having arms B4- 24 which embrace the projections 17-17 and are pivoted thereto on fixed rivets 5- 25: and the other of said pieces having arms 2S-Q6 adapted to enter the spaces betweenthe lips 14-14 of the contact. fingers and close the circuit therethrough. The'common base of these members is indicated at 27. Ateach side of the pivot the tip of the projection 17 is bent outwardly as shown at 28 to provide stops limiting the movement of the contact member.

The actuating devices for moving this contact member are carried by the plates 20-.-20 and consist of two opposed hammers one of which is illust-rated in perspective in Fig'. 4f. The bpdy of each of these hammers is made o'l' a single apertured piece of sheet metal bent tov produce twol parallel sides 30-30 connected.by,the integral web 31, the lines of bending traversing said aperture so that the latter produces a deep notch 32 which separates the web into two spaced portions. One extremity of each of these devices is pivoted between the plates 20-20 by means of the pins 33-33, their notches 32-32 facing each other and the webs 31 at their free ends constituting striking por tions so located relatively to the movable switch member as te contact with the portion 27. These hammer members are drawn yieldingly towards each other by means of a spiral spring 35, their approaching' movement being limited by suitable pins 36 carried by the plates 20-,-20. Pivotally mounted upon a transverse pivot 40 carried at the free-end of leach ot the hammer-members is a dog 41 having' an angularly pojecting tail 42 yieldingrly held against a stop-pin 43 by means oi a suitable spring 44 carried bythe hammer. 1

Slidably mounted inside the channel-member 16 is the operating; member of the switch, which ronsists'ot a ll shaped metal bar l5 whose lower end is here shown as connected to the member 4 symholizing any kind ot actuatinedevice whatsoever. At its middle portion the sides ot this bar Vare extended as shown at 46 in Figs. '6 and 7, producing a pair of apertured ears 4&7 and at each side thereof a deep notch 48. Pivoted inside the walls ot' themember 16 opposite each of the hammer members is a lever shown in` Fig. 5. con'iprising spaced side-members 50u50 and a connecting web 51 adjacent to its free end, each of said levers being traveised by a rivet 52 which itsin one of the notches 48. The member therefore projects between the two side members of each level' 'and is here shown as guided by the rivets 53 which support those levers. rlhe ears 4- 7 are connected by a rivet 54 which receives the slotted end of the fork 55 whose handle projects loosely through a hole 57 in the base of the movable contact member, this handle beingsurrounded by a spring 58. As aconsequence of this construction, recipro cation of the member 45 causes the'rivet 54 to pass by the rivet 25, and also causes the levers`50-50 to describey the arcs b-a shown in rig. i.

The operation ot `the switch is as follows:

` verse movement.

lwhich produces the operation.

renew/r Starting with the parts in the position shown in Fig. 1, a downward motion of the member 45, whether produced by the member 4 or otherwise, will cause the lowermost lever 5() to. swing downwardly. lnasmuch as its arc intersects the end of the dog al, the` dog and its attached hammer are caused to accompany .this movement, thereby displacing the strikingportion of the hammer away from the movable switch member with which it was previously in contact, and exerting tension on the spring 35. Meanwhile the other lever 50 comes in con-tact with the corresponding dog, but the yielding nature of the same when approached from lthis side permits the lever to p'ass freely by without displacing the upper hammer. Owing to the .fact that the arcs defined by the levers and hammers rapidly diverge, the time soon comes when the lowermost dog escapes past the vend of its lever whereupon the lower hammer, impelled by the spring 35, strikes the switch member 26 a sharp blow drivingit out of engagement with the Contact tingers 14; and inasmuch as the pivot 54 has meanwhile been moved pastthe pivot 25, which constitutes the dead center of the spring 58, the action of said spring is to hold such member in the position shown inphantom at to which it was thrown by the hammer. ln this way a'very sharp and quick breaking of the circuit is effected; besides the inertia of the contact member, coupled with the tension of the spring 58 causes that member not only to rest against the opposite hammer but even to displace that hammer a little Way, thus leaving the contact member always in position tor re lt is idle to speculate whether it is the-hammer or the spring The hammer at least starts the movement and is es-V i sential to the device; the spring may per-Y haps complete the movement and helps hold arts in place for the next operation,

but 1S not indispensable it the ineitia of the hammer is properly chosen and if suitable means are employed to hold the p'arts in place.

lf it now be desired to close the switch,

either thermostatically or otherwise, an upward movement of the member 45 produces identically the same operations as before exi cepting in reverse order with the result that the movable member is again driven into place between the contact fingers 14 exactly.

as shown in Fig. 1. rllhis switch offers special advantages in connection with a thermostat owing' to the fact that actuation can be produced by a comparatively small amount oit force and with a very small movement of the member 45. The rapidity of movement ot' the levers .50#-50 can he varied it desired hifi' changing the distance between the pivots 52 and 53, and the point of divergence of the arcs defined by the levers and their corresponding hammers canbe vayried by changing the relative positions of the bending of said spring but with this ad-' vantage that the` hammers initiate the movement of the contactmember at an accurately determinable time which is earlier than would be produced by the spring alone and requires a smaller amount of movementof the operating member.

The entire switch mechanism can,'if desired, be grounded, o r; it can very easily be insulated merely by inserting a strip of mica between the two .bases of the members 24 and 26, and making the handle 56 of the yoke of non-conducting material. All the parts of the switch are simple, are few in number, and can be-made from sheetA metal by simple process. However I do not restrict myself to any of the Constructions, arrangements, relations or designs described or illustrated herein except as the same are specifically recited in the annexed claims.

Having thus described my invention what I claim is:

1. 4In an electric switch, in combination, a pair of contact members, one of which is movable, a pair of opposed hammer-mem bers arranged facing each other upon opposite sides of said movable member, and

with the other contact member.

2. lIn an' electrc'switch', in combination, a pair of contact members, one of which is movable, a pair of opposed hammer-members arranged facing each other upon 0pposite sides of said movable member, means for producing a quick blow of either of said hammer members against said movable contact member for moving it into or out of engagement. with the fixed Contact member, and means for holding said movable member into which ever eXtreme of its movement it is impelled by said hammer members.

3. In an electric switch, the combination with a pair of spaced pivoted hammers, of a movable contact member located between them and adapted to be struck by the hammer nearest thereto, means movably maintaining lsaid contact member lin contact with one or the other of said hammers, and means for operating that hammerfor driving said member to the other hammer.

4. In an electric switch, in combination, a movable contact member pivoted to swing between limits, spring means normally holding said member at one or the other of such limits, a pair of hammers located one at each of such limits and adapted to be engaged by'said member, and means for first retracting that hammer which momentarily is engaged by said member and then impelling it violently against sai-d member, whereby said member is driven toward the other hammer.` y

5. In an electric switch, in combination, a movable contact member, an operating member, va pivoted hammer, and operative con. nections between said operating member and `hammer adapted upon recip-rocatio-n of the former to actuate the latter to strike violently against said mo-vable contact member in the line of direction of its movement, said connections including a dog carried by the hammer in position for engagement by the operating member.

6. In an electric switch, in combination, a movable contact member, a pair of hammers located 0n opposite sides thereof, a recipirocable operating member, and means operatively connecting ysaid operating member with each of. said hammers whereby upon movement of the former one or the other otsaid hammers vwill be caused to-strike the movable contact member and move the same f ina direction determined by the direction ot movement of said operating member.

7. In an electric switch, in combination, a movablecontact member, a pair of ham# mers located on opposite sides thereof, a. `reciprocable operating member, a deadcenter spring operatively connecting said members, and means actuated by the same movement of said operating member which causes a movement producing'tendency on the part of said spring for causing the cor- `responding hammer to strike said contact member and drive it in the same direction as indicated by said spring.

8. In an electric switch, in combination, a pivoted contact member, a. pair ot hammers located one at each limit ofl swinging movement ofsaid contact member, a reciprocable operating member movable past such pivot, a dead center spring connected between said members and movable past such pivot., and means connected to said operating member and engaging said hammers alternately to actuate them to drive Asaid contact member in the direction indicated by said spring.

9. In an electric switch, in combination. a supportja contact member pivoted thereto, a pair of levers pivoted to said support, one at each side of said contact member, a second support, and a pair of hammers pivoted thereto, one opposite each lever. and adapted to strike said contact member, the are ot movement oi each lever intersecting the arc of movement of the corresponding hammer. an operating member adapted t'o swing said levers to displace one or the other of said hammers, and spring means for thereafter returning said hammer with a blow which displaces said contact member.

10. In an electric switch, in combination,

a pair of pivoted hammers, a lever pivoted 'opposite each hammer, the arc of movement of each lever intersecting that of the .correspending hammer, spring means tending to` move sa1d hammers toward each other, ai movable contact member located between said hammers, and an operating member for -said levers adapted to swing the same in a direction to displace one of said hammers until it reaches the point of intersection of such arcs and then to allow said hammers to strike said contact member in movement producing relation.

mesma mined time compared with the movement of Y said-spring 'for inltiating the movement of said 4contact member which said spring tends to produce.

12. n automatic controlling mechanism, the combination with a reciprocable member of an electric switch comprising a reciprocable operating member, a pivoted contact member, a spring connected thereto and movable by said operating member to opposite sides of the pivot axis, and spring ham-- mers actuated by the same movement otl said opera-ting,r member to strike said contact member as soon as said spring has reached a predetermined position relative to said pivot axis for initiating movement of said contact member in the direction sought to be produced by said spring.

In testimony whereof, signature.

SAMUEL H. from).

I hereunto aiiix my l 

